Pixel Width of the text in a UILabel

NSString has a sizeWithAttributes: method that can be used for this. It returns a CGSize structure, so you could do something similar to the following to find the width of the text inside your label.

iOS 7 and higher

CGSize textSize = [[label text] sizeWithAttributes:@{NSFontAttributeName:[label font]}];

CGFloat strikeWidth = textSize.width;

iOS <7

Prior to iOS7, you had to use the sizeWithFont: method.

CGSize textSize = [[label text] sizeWithFont:[label font]];

CGFloat strikeWidth = textSize.width;

UILabel has a font property that you can use to dynamically get the font details for your label as i'm doing above.

Hope this helps :)

A better solution, here in Swift:
Update:
For Swift 3/4:

@IBOutlet weak var testLabel: UILabel!
// in any function
testLabel.text = "New Label Text"
let width = testLabel.intrinsicContentSize.width
let height = testLabel.intrinsicContentSize.height
print("width:\(width), height: \(height)")

Old Answer:

yourLabel?.text = "Test label text" // sample label text
let labelTextWidth = yourLabel?.intrinsicContentSize().width
let labelTextHeight = yourLabel?.intrinsicContentSize().height